ADR A-04: Interval containment and overlap law split

Status

Accepted

Context

Eligibility previously treated interval overlap as interchangeable with interval containment in some profiles. That is not law-coherent for admissibility. Overlap can be true while containment is false, and overlap does not provide a safe basis for determining admissibility where full inclusion is required.

Decision

Eligibility adopts IntervalContainment as the only interval strategy for admissibility decisions in the substrate model.

• IntervalContainment uses qnt:Range and qnt:RangeSet from Quantification.
• IntervalOverlap is excluded from the admissibility strategy algebra.
• Any profile needing overlap for screening must model it as a separate, non-admissibility pre-check outside eligibility decision laws.

Consequences

• End-to-end admissibility remains law-coherent.
• Quantification supplies all required interval structures, so no exemption or bootstrap mechanism is needed.
• Screening use cases still remain possible, but they cannot be represented as admissibility outcomes in Eligibility.